The Valve,check, cataloged under National Stock Number 4820-00-176-4536, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp. Government technical data includes 17 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-176-4536 |
| Primary Part Number | SS50-815K8C |
| Item Name | Valve,check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | FLARED (TUBE) ALL ENDS |
| Mounting Position | HORIZONTAL |
| Connection Type | THREADED EXTERNAL TUBE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Material Document and Classification | QQ-S-763,CLASS 316 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.500 INCHES ALL ENDS IN |
| Seat Angle | 37.0 DEGREES ALL ENDS |
| Disk Loading Method | SPRING |
| Surface Treatment | PASSIVATE |
| Media for Which Designed | HYDRAULIC FLUID, PETROLEUM BASE SINGLE RESPONSE |
| Thread Class | 3A ALL ENDS A |
| Material | STEEL COMP 316 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) ALL ENDS |
| Valve Operation Method | AUTOMATIC |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| SS50-815K8C | Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp (USA) |
| Reference | Meaning |
|---|---|
| SS50-815K8C | 3/2 Design control — primary reference U.S. Government activity |
| SS50-815K8C | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-00-176-4536 is a Valve,check, manufactured by Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-176-4536 has 1 manufacturer part number on file: SS50-815K8C (Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp).
Key specifications for SS50-815K8C: Flow Control Device: DISK; Connection Style: FLARED (TUBE) ALL ENDS; Mounting Position: HORIZONTAL; Connection Type: THREADED EXTERNAL TUBE ALL ENDS. 17 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.